Intrinsic magnetic, structural and resistivity properties of ferromagnetic Mn0.5Zn0.5AlxFe2−xO4 nanoparticles

• Published in: Materials research bulletin 2013-03, Vol.48 (3), p.1189-1196
• Main Authors: Haralkar, S.J., Kadam, R.H., More, S.S., Shirsath, Sagar E., Mane, M.L., Patil, Swati, Mane, D.R.
• Format: Article
• Language: English
• Subjects: A. Magnetic materials; B. Sol–gel chemistry; C. Infrared spectroscopy; C. X-ray diffraction; D. Magnetic properties
• ISSN: 0025-5408; 1873-4227
• DOI: 10.1016/j.materresbull.2012.12.018

[Display omitted] ► Al3+ ion substituted Mn–Zn ferrite nanoparticles. ► Single phase cubic spinel structure changes with Al3+ substitution. ► Magnetization and coercivity decreased with increasing Al3+. ► Resistivity increased with Al3+ substitution. In this work the nano-structural, magnetic and resistivity properties of Al3+ substituted Mn–Zn ferrites powders were investigated. Mn0.5Zn0.5AlxFe2−xO4 powders, where x=0.0, 0.1, 0.2, 0.3, 0.4 and 0.5 were obtained by the sol–gel auto-combustion method. X-ray diffraction data indicate that, after substitution, all the samples consisted of the main spinel phase in combination with a small amount of a foreign Al2O3 phase. The addition of Al3+ resulted in a reduction of particle size and density of the prepared samples. Cation distribution in the present study was estimated by using X-ray diffraction data. The tetrahedral site radii initially increased with Al3+ content while the octahedral site radii decreased with the Al3+ substitution. FTIR spectra show two strong absorption bands at 529–548cm−1 and 445–452cm−1 which are the typical bands for the cubic spinel crystal structure. The magnetic properties were measured by employing a vibrating sample magnetometer. It was observed that the saturation magnetization, coercivity and anisotropy field decreased with the increase of Al3+ substitution. Introduction of Al3+ ions into the Mn–Zn ferrite increased the values of the resistivity, especially in the lower temperature range.